Archive for the ‘Eagle’ Category

For a little over a year, I’ve been working on an open-source, DIY cellphone as part of my PhD research at the MIT Media Lab. The current version of the phone is based on the Arduino GSM shield and Arduino GSM library. It sports a deliberately low-resolution screen (8 characters, each a 5×7 matrix of LEDs), a laser-cut wooden enclosure, flexure (living hinge) buttons, and a ~1000-line Arduino program that powers the user interface. The phone can make and receive phone calls and text messages, includes a phone book and caller id, and keeps the time. Everything you’d expect from a 20-year old Nokia! (Except snake.) I’ve been using various iterations of the project as my primary cellphone for the past six months or so.

The phone is open-source and the design files are available on GitHub (hardware, software). Assembly instructions are on my website, although I wouldn’t recommend making your own unless you have experience with soldering surface mount components.

Of course, it’s not just me that’s been building these phones. I’ve run twoworkshops in which other people have made them for themselves. A few people have been building them on their own, including someone who posted his result on Twitter.

Here you can see some the variations on the enclosure that my friends have made. On the left is a 3d-printed case by Ben Peters, the middle is a CNC-milled purpleheart wood case by Dena Molnar, and on the right is a hand-cut cardboard case by Jeffrey Warren.

The phone has undergone numerous revisions as I’ve tried to get it into a robust, useable form. Here you can see some of those variations. I started with an LCD screen like those found on old Nokia phones, but it would break after a month or so in my pocket, so I switched to the more-robust LED matrix. The enclosure has had a few tweaks as well, primarily to find a good design for the flexure buttons.

Overall, I’m pretty happy with the current incarnation. It seems to be relatively robust, simple enough to assemble by hand, and functional enough to use everyday (although a long way from a smart phone). That’s my DIY cellphone.

There are many Quadrotor Projects out there. But, they require a hobbyist to deal with the Frame Designing (Mechanical), a bit of Microcontroller knowledge as well as dealing with the Motor Control (Power Electronics). You may purchase a commercial Radio and a readymade Kit for flying. But, to Do-It-Yourself, is an achievement in itself.

Here is a picture of a Quadrotor designed by Shane Colton using Arduino Pro mini as its flying brain. Shane is a Ph.D Student at Massachusetts Institute of Technology. On being asked about the Project, he replied:

I heard about Arduino some time in 2007/2008 and have used it for a few projects since then. I built the quadrotor for fun / hobby (not related to research). I wanted to build my own (quadrotor) from scratch because I could integrate all the parts onto a single circuit board, and because I like designing the control system myself.

As a hobbyist, we often want to extend the functionality of our arduino board. In order to minimize wires and maximize functionality, we design special need-based ‘shields‘. A useful step by step tutorial that I found here , breaks down the process into the following stages:

Sensebridge is a little board that logs up to 61831 heart beats, about 14 hours of data. It is based on a atmega 168, a Real Time Clock, and 512 Kbit EEPROM. And it’s released open source.

The Heart Spark is a heart-shaped pendant which flashes little lights (light emitting diodes, LEDs) in time with your heart beat. A polar chest strap with transmitter (sold separately) is used to measure your heart beat, which is transmitted wirelessly to the pendant. An arduino-compatible circuit captures each beat as it happens and flashes LEDs (later versions will log data to an onboard EEPROM – see below). The pendant is carefully designed to maximize its visual appeal, including symmetry and optionally a high-gloss epoxy coating (as pictured to the right). A CR2032 coin-cell battery provides 8+ hours of battery life. Two small switches on the back allow selection of operating mode:

Sensebridge is a little board that logs up to 61831 heart beats, about 14 hours of data. It is based on a atmega 168, a Real Time Clock, and 512 Kbit EEPROM. And it’s released open source.

The Heart Spark is a heart-shaped pendant which flashes little lights (light emitting diodes, LEDs) in time with your heart beat. A polar chest strap with transmitter (sold separately) is used to measure your heart beat, which is transmitted wirelessly to the pendant. An arduino-compatible circuit captures each beat as it happens and flashes LEDs (later versions will log data to an onboard EEPROM – see below). The pendant is carefully designed to maximize its visual appeal, including symmetry and optionally a high-gloss epoxy coating (as pictured to the right). A CR2032 coin-cell battery provides 8+ hours of battery life. Two small switches on the back allow selection of operating mode:

If you’re looking to make your own shield for the Arduino platform, you’ll definitely need to know where all the pins and holes are located on the Arduino. After doing a quick search, I was unable to find an accurate technical drawing of the new Arduino UNO and Arduino Mega 2560.

Using the PCB design files available at the Arduino hardware website, I created a detailed technical drawing of both the Uno and Mega 2560. The drawings are available in vector-based SVG format, but low-resolution PNG files are shown below (click for larger versions). All drawings are released into the public domain, but let us know if you find any mistakes or have any suggestions or updates.

new edition has bugs fixed from 1st version, larger screen (16×2 characters) and i’ve added an op amp with bass boost and distortion feature, design by blushing boy, AKA david cuartielles. taken from his smapler board.

a few extra design goodies have been added, like walkman-like volume control, and a pixel ghost for extra prototyping.

i am only making 25 pcs. some will be sold at piksel, some at MFRU. pre-order yours today!

thanks to david gauthier for helping out with the more tricky parts of eagle CAD.

new edition has bugs fixed from 1st version, larger screen (16×2 characters) and i’ve added an op amp with bass boost and distortion feature, design by blushing boy, AKA david cuartielles. taken from his smapler board.

a few extra design goodies have been added, like walkman-like volume control, and a pixel ghost for extra prototyping.

i am only making 25 pcs. some will be sold at piksel, some at MFRU. pre-order yours today!

thanks to david gauthier for helping out with the more tricky parts of eagle CAD.

new edition has bugs fixed from 1st version, larger screen (16×2 characters) and i’ve added an op amp with bass boost and distortion feature, design by blushing boy, AKA david cuartielles. taken from his smapler board.

a few extra design goodies have been added, like walkman-like volume control, and a pixel ghost for extra prototyping.

i am only making 25 pcs. some will be sold at piksel, some at MFRU. pre-order yours today!

thanks to david gauthier for helping out with the more tricky parts of eagle CAD.

new edition has bugs fixed from 1st version, larger screen (16×2 characters) and i’ve added an op amp with bass boost and distortion feature, design by blushing boy, AKA david cuartielles. taken from his smapler board.

a few extra design goodies have been added, like walkman-like volume control, and a pixel ghost for extra prototyping.

i am only making 25 pcs. some will be sold at piksel, some at MFRU. pre-order yours today!

thanks to david gauthier for helping out with the more tricky parts of eagle CAD.

new edition has bugs fixed from 1st version, larger screen (16×2 characters) and i’ve added an op amp with bass boost and distortion feature, design by blushing boy, AKA david cuartielles. taken from his smapler board.

a few extra design goodies have been added, like walkman-like volume control, and a pixel ghost for extra prototyping.

i am only making 25 pcs. some will be sold at piksel, some at MFRU. pre-order yours today!

thanks to david gauthier for helping out with the more tricky parts of eagle CAD.

new edition has bugs fixed from 1st version, larger screen (16×2 characters) and i’ve added an op amp with bass boost and distortion feature, design by blushing boy, AKA david cuartielles. taken from his smapler board.

a few extra design goodies have been added, like walkman-like volume control, and a pixel ghost for extra prototyping.

i am only making 25 pcs. some will be sold at piksel, some at MFRU. pre-order yours today!

thanks to david gauthier for helping out with the more tricky parts of eagle CAD.

So you’re pretty fond of your Arduino. You make blinking lights, and beeping noises. You’ve made a robot that was pretty cool. Or maybe you didn’t. Who cares, You’re ready for the next step. You want to extend it. Although you can just plug in wires, there’s something very appealing about making a shield. Instead of a rats-nest of wires piled about and plugged into your prototyping breadboard, you can have a nice clean shield with labeled connections and a smaller footprint. So here I’m going to tell you everything you need to know to make a schematic and PCB layout, and get a beautiful shield that will plug into the top of your Arduino.

Searching on the net on Arduino and Arduino web-sites you will find a lot of projects and ideas about the use of EEProm devices as a non-volatile storage method to save data. Arduino is equipped with its own – very small – EEProm memory to save configuration parameters and much more. Arduino boards have about 32 Kb – or even less – storage area and users experience the need to expand it in an affordable and robust way.

The development of a memory bank based on I2C bus EEProm relates to the creation of some kind of software in order to offer at least the possibility to access every memory location regardless of the number and kind of physical devices actually used. Following this way, we developed this memory Bank, aka EEProm 128×8 in respect of these requirements. After having carried out tests and made changes to the first hardware prototype, we are now releasing hardware version 2.1, part of the Bank project 1.2